Problem: $ { \left[\begin{array}{rrr}{-2} & {1} & {4} \\ {0} & {0} & {4}\end{array}\right]-\left[\begin{array}{rrr}{-2} & {4} & {0} \\ {0} & {1} & {1}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rrr}{-2}-{-2} & {1}-{4} & {4}-{0} \\ {0}-{0} & {0}-{1} & {4}-{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{0} & {-3} & {4} \\ {0} & {-1} & {3}\end{array}\right]}$